Regardless of the light then the camera will maintain the shutter speed and the aperture by adjusying the iso.

On the 1D4 you also get the option to set exposure compensation to ensure correct metering

If I'm shooting in Manual (that's all I do) why would I want to sacrifice image quality and noise by allowing the camera to set different ISO's?

That's what I don't understand.

The use of Auto ISO allows the camera to correct exposure when moment-changes occur. I can't say how many times I ended up underexposing because a cloud rolled in front of the sun just before I started shooting. (For all my technical knowledge, I'm still a novice when it comes to bird photography...I understand the technical factors and techniques, I'm just not that great at using them in the field yet. ) For BIF, you really can't redo the shoot. Using Auto ISO and EC, the camera could automatically compensate for the change in lighting, but you still have ultimate control over exposure.

As for noise, generally speaking if you underexpose and lift exposure in post, you'll still usually end up with more noise. Digital exposure adjustment always affects noise as well (since at that point its baked into the RAW), so lifting an underexposed photo will have as much or potentially more noise than using a higher native ISO setting. At worst the end result is roughly the same, at best using Auto ISO+EC in camera would produce better results.

Say you are shooting an Egret at 1/1000 sec @ f/8, with an ISO of 400. Perfect light and exposure confirmed by following the histogram…. Right?

A cloud comes in and diffuses the light. All I have to do is to reduce the shutter speed to say… 1/500 sec (one f/stop) and continue achieving a good exposure without sacrificing noise by allowing the camera to chance the ISO. If the cloud rolls out, my shutter speed will of course return to 1/1000 sec which I already know is a good and confirmed exposure based on the previous light.

That’s two or three click to the left and right on the top dial.

My point is that you can easily achieve the same results without sacrificing noise and more importantly…. Image quality.

If 1/500 s works for you in that shot, great. But if I need 1/1000 s for the effect I want to create with the shot, then a one stop lower shutter speed does not work for me. It's not a question of whether one can get a good result with a lower shutter speed, the issue at hand is I want to choose the shutter speed. That's what M mode is all about. Having exposure compensation easily accessible with the rear dial in M mode is convenient. Is it necessary? No. But for that matter, neither are autoexposure, autofocus, or high speed continuous shooting. But all of those are convenient, as would be EC in M mode.

Say you are shooting an Egret at 1/1000 sec @ f/8, with an ISO of 400. Perfect light and exposure confirmed by following the histogram…. Right?

A cloud comes in and diffuses the light. All I have to do is to reduce the shutter speed to say… 1/500 sec (one f/stop) and continue achieving a good exposure without sacrificing noise by allowing the camera to chance the ISO. If the cloud rolls out, my shutter speed will of course return to 1/1000 sec which I already know is a good and confirmed exposure based on the previous light.

That’s two or three click to the left and right on the top dial.

My point is that you can easily achieve the same results without sacrificing noise and more importantly…. Image quality.

Good talk!

Thank you

You could do that, but you have to keep in mind the side effects of changing shutter speed or aperture. Both are indeed used to adjust exposure, but they have distinct side effects. A lower shutter speed will increase blur...both blur from motion as well as blur from camera shake. A wider aperture will reduce your depth of field, potentially to the point where half your subject is out of focus when you wanted the whole thing in focus.

At 1/500th with a 400mm lens, I experience just enough camera shake blur when hand-held for it to blur detail when shooting hand-held, even with IS (admittedly, the IS on my 100-400 isn't a modern 4-stop version). Additionally, 1/500th of a second exposure can cause more wing motion blur than I want in some cases. I liked your 1/30th second shot of the heron, but you don't always need that low of a shutter speed to get a nice, artistic amount of motion blur in wings. A fast moving bird with a fast wing beat at 1/800th - 1/1000th produces enough of blur for my tastes most of the time. In that case, I really want to keep my shutter speed between a pretty narrow range, limiting my ability to adjust it if exposure correction is needed. If I require a specific aperture to achieve enough DOF to get a whole bird, say a large bird like a pelican, in focus while tracking it in flight, the only thing I can vary at that point without worrying I'll impose undesirable side effects is ISO.

I could certainly change ISO manually (and I always do, given that I use a 7D and don't have the option of EC in M), but if I had exposure compensation against Auto ISO in manual mode, that makes the adjustment so much easier. I don't need to drop into a specific camera mode to change ISO to my desired level, exit that mode, then focus/lock and track my subject. With EC, it would simply take the roll of a dial to achieve the exact same thing, but without losing the instantaneous ability to adapt to changing lighting circumstances. Its definitely a convenience thing...but convenience means I spend more time watching the birds (and getting keepers) and less time watching my settings.

Regardless of the light then the camera will maintain the shutter speed and the aperture by adjusying the iso.

On the 1D4 you also get the option to set exposure compensation to ensure correct metering

If I'm shooting in Manual (that's all I do) why would I want to sacrifice image quality and noise by allowing the camera to set different ISO's?

That's what I don't understand.

The use of Auto ISO allows the camera to correct exposure when moment-changes occur. I can't say how many times I ended up underexposing because a cloud rolled in front of the sun just before I started shooting. (For all my technical knowledge, I'm still a novice when it comes to bird photography...I understand the technical factors and techniques, I'm just not that great at using them in the field yet. ) For BIF, you really can't redo the shoot. Using Auto ISO and EC, the camera could automatically compensate for the change in lighting, but you still have ultimate control over exposure.

As for noise, generally speaking if you underexpose and lift exposure in post, you'll still usually end up with more noise. Digital exposure adjustment always affects noise as well (since at that point its baked into the RAW), so lifting an underexposed photo will have as much or potentially more noise than using a higher native ISO setting. At worst the end result is roughly the same, at best using Auto ISO+EC in camera would produce better results.

Say you are shooting an Egret at 1/1000 sec @ f/8, with an ISO of 400. Perfect light and exposure confirmed by following the histogram…. Right?

A cloud comes in and diffuses the light. All I have to do is to reduce the shutter speed to say… 1/500 sec (one f/stop) and continue achieving a good exposure without sacrificing noise by allowing the camera to chance the ISO. If the cloud rolls out, my shutter speed will of course return to 1/1000 sec which I already know is a good and confirmed exposure based on the previous light.

That’s two or three click to the left and right on the top dial.

My point is that you can easily achieve the same results without sacrificing noise and more importantly…. Image quality.

Good talk!

Thank you

You are not listening - getting the camera do set the iso can improve the IQ and reduce the noise because it can react quicker than the shooter as the bird flies from shade to sun. You will always get the correct exposure and therefore more keepers

Your method of adjusting the shutter speed will change the blur and therefore the composition quality.

I would love to see how you adjust the shutter speed fast and accurately enough to capture a raptor coming out of the sun into the woods

The 1D4 wins out on the low light stakes - doing iso 6400 without breaking a sweat

Picked up a used 1D MK IV yesterday, only 1440 actuations, so its basically new. I bought it based solely on your recommendation, so I'm holding you responsible.

Just as a hedge, I have a D800 coming next week to try out, but its a totally different camera. Ec in manual mode does seem to me to be a nice feature as is the AF point linked to the exposure meter.

At the same price as a 5D MK III, I think I will love the MK IV.

I'm in doubt about the D800 with respect to the editing of the very large files, but I'm thinking landscape for it. I will use the f/8 capabilities of the MK IV as well, but not the D800, since Nikon does not have any comparable lens to the 100-400L.

1D mk IV AF at f8 is a little slower, but yes, it seems to be accurate. I have been using it for a few weeks, and as an ameature used to a 7d, I was not impressed with AF outside of single point to be frank. I just leave it on center point and adjust the framing. My 7d seems faster having to only deal with 19 points instead of the 1D Mk IV's 45 points. I am waiting for the 1Dx to be shipped and see how different the AF system is.

briansquibb

1D mk IV AF at f8 is a little slower, but yes, it seems to be accurate. I have been using it for a few weeks, and as an ameature used to a 7d, I was not impressed with AF outside of single point to be frank. I just leave it on center point and adjust the framing. My 7d seems faster having to only deal with 19 points instead of the 1D Mk IV's 45 points. I am waiting for the 1Dx to be shipped and see how different the AF system is.

It is so easy and quick to move the AF point around with the 1D4 that I persevered and that is the only adjustment I make on the fly. With the single AF point there is no way the 7D is faster.

Sample images with EXIF? (Sorry to be a skeptic, but this is pretty much THE issue of the day for bird photographers, and the word from Canon has been pretty explicit this far: 61pt AF only works to f/5.6).